Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

Exactly one lunar month after the failure of Kosmos 300, the Soviets launched another Ye-8-5 lunar sample-return spacecraft. Once again, the spacecraft failed to leave Earth orbit.

When the Blok D upper stage was meant to fire for translunar injection, telemetry readings went off-scale and communications were lost. There had apparently been a programming failure in one of the radio-command blocks designed to command the Blok D to fire.

The Soviet press merely referred to the probe as Kosmos 305. The spacecraft's orbit decayed over Australia before the craft completed a single orbit of Earth.

Key Dates

22 Oct 1969: Launch

Status: Unsuccessful

Fast Facts

Fourth Soviet attempt to return samples from the Moon.

A programming error is believe to have led to a loss of communications and the booster rocket to carry the spacecraft out of Earth orbit never fired.

The Soviets renamed it as part of the Kosmos series of Earth-orbiting missions to disguise its true purpose to visit the Moon.